Compound rotary engine



(No Model.) 2 ySmeets-She@ 1.

R. H. ISBBLL, l v GvoMPoUND ROTARY ENGINE.

N0.586,497, Patented Ju1y13,1897.f

UNITED STATES PATENT* OFFICE.,

uonER'rn. ISBELL, or, WooDLAWN, NEWXEK.

coMPouNo ROTARY ENGINE. 'f

SPECIFICATION forming part of Letters Patent No. 586,497, dated July 13,1897.

Application il'sd December 4, 1896. ISerial-No. 614,425., (No medel.)

T LIZ 'whom it may conccn):

lle it known that I, ROBERT II. ISBELL, a

citizen of the United States, residing at lVoodlawn,v in the city,county, and State of New York, have inventeda Compound Rotarylilngine,of which the following is aspeciiication.

This engine is made for using the steam eX- u pansively, and with' thisobject in view the pistons arc compound 'and pivoted, theinner leaf ofeach piston resting at its edge against a stationaryhub that isapproximately round,

and the outer leaf of the pistontravels against t-he interior 'surfaceof the ease, andthese pistons, preferably three in4 number, areconnected with a cylinder that is supported by a head and av shaft fromwhich the power is taken, and the hub and case are eccentric to therotary cylinder, so that there are inner and outer steamehambers, theinner leaves of the pistons: being acted upon within the innersteam-chamber by high-pressure steam and the outer leaves of the pistonsbeing acted upon in the out-er chamber by the steam as it expands, andthe same finally passes off at the exhaust. In this engine the twosteamchambers are crescent-shaped and stand in reverse directions.

In theV drawings, Figure l is a cross-section through the engine. Fig. 2is a sect-ion upon the line 2 2.of Fig. l. Fig. 3 shows the interiorsurface of the case with the inlet-steam port and the transfer-port.Fig. #i is a side view oJf the cylinder and outer pistons. Fig. 5 is anend view of the shaft and cylinder.

Fig. G shows the inner side of the removable head, and Fig. '7 is asectional illustration ofthe passage for the steam that first acts onthe outer piston.

The case of the engine is made with a stationary head A and a nearlycylindrical or barrel portion B, and there is a removable head C, thatis bolted upon the case at 5, and this removable head O carries thehuhl).

The main shaf t E passes through the gland or stufiing-box' and issupported in a socket. within vthe hub D, and there is advantageously anaxjial hole for the inscrtionof oil. lfrojectin'g frointhe main shaft Eand preferably made with the sanie is thehcadF, ,l ioavhic'li vispermanently connected the cylinjder (i,".wliiclris made up ofthreefparts permanently connected at one end'to the head ,asthcc'ylin'der passes t'li ring 8 is supported by and travels inacircular groove in the removable head C, and in consequenceof ltheinteriorrof the'barrel'B being eccentric to the shaft E andapproximatelycircular there is a crescent-shaped steam-chamber 9 between the outersurface of the cylinder G and the interior of the barrel or case B, thecylinder 4Gr setting closely against the interior surface of the case Bat one side and the hub D setting closely against the interior surfaceof thecylinder G at the other ,side,landsuch hub being eccentricfto thecylinderV G there .is a crescent-shaped; steamchamber lvbetweenthe hub DIandthe i F and at the other end to the yring 8, which l interior of thecylinder G, audit is now tobe l l understood that` theV chamber lO is4for .high

pressure and the chamber 9 for lowipressure,

the steam actinglexpansiyely,in the latter. i-

The pistons; `H are each-v advantageouslyin made With'aninner leafll and-ann 'outer leaf 12 and supported upon apivot-pin 13, and thispivot-pinl 13 passes through the lring 8 into the head F,andtheseipistonsset closelygf: so as to b esubstantially'steainftight:at'the cylindrical or hinge portionrof' eachpiston, and the inner leaf ll is smallerthan the outer leaf 12,thechamber 9 beingiugi'der than the chamber l0, and it istolbe,.understoody;:that

:thev

the distance between the',outei-edge ,l Y leaf l2 and the inner edgeof`the .leafll corresponds, or nearly so',- to` thedistancebetvveen theinnersurface of the case B `andtheouter surface kof the hub D attheplaeesof contact,

so that as the'pistons travel around-withthe cylinder- G their. edgesremain incontact, yor

, nearly so, with the .surfaces named.

The outer surfaces of theV cylinderl Gare recessed, so as to allowtheoutfer leaves'l of the pistons H to passim-to suchrecessesas thecylinder moves pastthegab'utnient.14,l or point of contact of thecylinde 'f lftheinterior of the case B, andf tl ,inner surfaces intothem-the inner leaves lof th y point vof contact jbetjweent innersurface ofthe cylindei The live steain. under tl'ie4 is admittedbythejpipe' i of 'the said crescent-'shaped' chamber. The

IOO

inlet-steam pipe I opens into a port 19, which is in the'stationa-ryhead A and extends part way around the same 'as an arc o f a circle, andthere is a similar-shaped transfer-port 17 in the head A, and a branch1S, passing from -such transfer-port and opening intoithe case B nearthe opposite end of the steam-chamthe ports'19 from .the steam-ports1b', and the high-pressure steam acts between the abutment 15 andone ofthe inner'leaves '11 to carry the pistons and cylinders in the directionindicated by the arrow, and the pressure continues active within thehigh -pressure chamber 10 until another pistonis brought around intoposition for steam to be admitted by the next port 19 to act upon suchinner leaf 11 and continue the movement, and the 4high-pressure steam iscut off from the first- 'named piston when its port 19 reaches the endof the steam-port 16, and the port 19 passes overthe inner surface 2Obetween the end of the steam-port 16 and the commencef ment of thetransfer-port 17, and as soon as such port 19 reaches the transfer-portthe ,high-pressure steam in the inner chamber .10 passes through suchtransfer-port 17 and the branchlS into the steam-chamber 9 to act uponthe outer leaf 12 of one of the pistons, which at this moment has beenbrought into proper position for the 'force of the expanding steam to beexerted upon the larger and outer leaf of the piston to carry the samearound to the exhaust-pipeIQand one piston is fully in operation by theexpanding` steam when the piston that isa-in front of it reaches theexhaustport, so thatlthere is `no back pressure behind the piston that.is in full operation, and so also the pressure acts in its full powerupon the inner leaf of onefpiston during the time that the high-pressuresteam is passing out from the preceding high-pressure-steam chamberthrough the transfer? port, and by using three pistons, each havin g,two leavesthe circle is advantageously divided up into sections ofonehundred and twenty degrees, and the outer leaf of one of the threepistons is at the .point of greatest power at the time the inner leaf ofthe next succeeding piston is going out of actionand the inner leaf of.the third piston is coming into action, the inner leaves of the pistonsexerting their greatest force as the outer leaf of one pistonis cominginto action and the outer leaf of the otherpiston is going out ofaction, so that the power exerted all around the 'main shaft E to rotatethe same is uniform, or nearly so, at all places.

In some instances I have used the engines with only the partshereinbefore described; but I find it advantageous to employ in additionports for admitting steam to act between th'e cylinder G and the outerleaf to 4press the edge of such outervleaf against the leaves intocontact with the exterior surface I' y 75 of the hub D and therebyprevent the escape of steam at the respective places and prevent anyhammering action that might arise from looseness of the respectiveparts; and with this object inview I provide channels or ports d in theinner surfaces of the cylinder G'at the bottom of the recesses intowhich theinner leaves 11-of the pistons are received, and these channelsa open at their ends by lateral holes into the ports 19, so that steamwill pass through these ports 19 and channels (c and act to press theinner leaves of the pistons in succession, so that they rest against theouter surface of the hub I) before the full force of thesteam admittedthrough one of the ports 19 acts between the inner leaf and theabutment. VI also provide a channel or port e in the bottom of each ofthe recesses receiving the outer leaves ofthe pistons, and these ychannels c openyat their ends through the head F, and it isimportant toadmit lv`e steam to act in these channels c, and with this object inview I make a U-shaped port 21 in the stationary head A between the endof the steam-port 16 and the beginning of the transfer-port 17, and theparts are soproportioned that as soon asone port 19 passesthe end of thesteam-port 1G, so that the surface roo 20 closes the port 19, theconfined high-presy i sure steam may pass through that port 19 andthrough the U-shaped port 21 andback through and into the h'ole at theend of the vleaf ofthe piston; which has by the aforesaid moveme'nt beenbrought into position for the` stealn to expand and exert its forceagainst that piston in continuing the movement of the cylinder G and itsshaft.

The aforesaid operations being performed in succession the full force ofthe expanding higlrpressure steam upon the inner loaves diminishes andthe eiliciencyV of the highpressure steam upon the inner leaves of thepistons increases as the elicicncy of theek-` panding pressurediminishes on. the outer leaves, thus equalizing the power exertedtorotate the main shaft, and either. the high pressure or the lowpressureis always opera- 1 steamvis in operation, as the efficiency of the tiveon each piston, there being two pistons acted upon by high 'pressure andone by low pressure, or the reverse. Hence power is always acting allaround the shaft to equalize strain and wear.

The engine is very simple, as there are but few parts to construct, andthey are not liable to get out of order or to wear rapidly, and the fullbenefit of expansion is obtained.

I claim as my inventionl. In a rotary engine, the combination with thecase and its heads and a stationary hub carried by one of the heads, ofa main shaft and its head, a cylinder carried by the head and pistons atequal distances around the cylinder each having a leaf projecting inwardand a leaf projecting outward, there being a port for thehigh-pressure-steam ports in the revolving head through which thehigh-pressuresteam passes to act upon the inner leaves of the pistons, atransfer-port for the highpressure steam to pass from the inner chamberto the outer chamber, and act upon the outer leaves of the pistons, andan exhaustport from the outer as set forth.

2. The combination in a rotary engine, of an outer case and its heads, ahub carried by one of its heads, a shaft eccentric to the hub and a headupon such shaft, a cylinder composed of sections and intermediatepistons having inner and outer leaves, a ring for connecting thesections of. the cylinder together and pivot-pins passing through thering and head and upon which the pistons swing, a steam-inlet port, andports through the head to which the cylinder is connected, a segmentaltransfer-port and branch for allowing high-pressu re steam from theinner chamber to pass into the outer chamber, and an exhaust' pipe orport from the outer chamber, substantially as set forth.

The combination in a rotary engine, of

by suchI head and pivoted pistons in the cyl-1 chamber, substantially amain shaft and head, a cylinder supported- 4s inder having innerandouter leaves, the cylinder being recessed for the reception-of suchleaves, and ports or pipes for allowing steam to pass into the recessesandbeneath therespective leaves of the pistons for moving such 5o leavesoutward or inward to bring their edges vintov contact with the interiorsurface-of the case or the exterior surface ofthe hub, substantially asset forth. l

4. The combination with the case and its heads,.of a hub. carried by oneof theh'eads, a main shaft, cylinder and pistonscarried by' such shaft,the pistons having inner and outer leaves to act within the crescentshaped steam-spaces between the cylinder and the case, and the cylinderand the hub respectively, the cylinder being recessed for receiving theleaves of the pistons, steam-ports for admitting pressure into therecesses for swinging the respective pistons out of such recesses and aU-shaped port in the head of the case for allowing such steam-pressureto act in moving the outer leaves of the pistons out of their recesses,substantially as set forth.

5. The combination in aprotary engine, of a stationary case and astationary central hub, an intermediate cylinder placed eccentric andpistons passing through and pivoted, upon the said cylinder and havingone leaf acted upon by pressure in the inner chamber and the other leafby pressure in the outer chamber, there being recesses into which oneleaf of each piston is swung while the other leaf is in action,substantially as set forth.

Signed by me this 30th day of November, 8o 1896.

ROBERT H. ISBELL.

Witnesses:

GEO. T. PINCKNEY, S. T. HAvILAND.

